The present disclosure herein relates to a substrate treating apparatus configured to treat a substrate, and more particularly, to a substrate heating unit configured to heat a substrate, and a substrate treating apparatus.
In a semiconductor manufacturing apparatus performing processes, such as forming of a semiconductor layer, etching, and treating of a resist layer, a heater for heating a substrate is used.
Since fineness of semiconductor device pattern and enhancement in the preciseness of heat treating temperature are required, a ceramic heater having an excellent temperature control characteristic is widely used for the heater. Such a heater is provided in a structure including a plate supporting a substrate, and a resistance heat generating member made of a composite material of metal particles and glass and attached on a rear surface of the plate.
Since the related art heater uses the plate made of a single material, the following problems may be caused. Since the plate is a metal material, if the plate is thin, bending, distortion, etc. of the plate may be caused under a high temperature state (about 200° C. or more). This thermal deformation may act as a factor destroying the substrate on the plate. On the contrary to this, if the plate is thick, the weight and volume of the heater may increase. Also, while heat generated from the resistance heat generating member is transferred to the substrate through the plate, much heat loss may be generated in an edge of the plate to a circumferential surface. This heat loss causes a difference in the heat flux supplied to the edge and a center of the substrate and thus becomes a factor non-uniformly maintaining the temperature of the substrate.